Realm of Magic: is it overwhelming?

I don't think it is overwhelming. You can easily choose which sims become spellcasters and it is perfectly possible to combine with a normal life. My spellcaster is currently working hard to get her degree in fine arts. To be honest I think it is best to combine their magic with a normal life so you don't rush through learning magic too quickly and enjoy it at a slow pace.

They are not as intrusive as vampires because there are no break ins or something similar. They are practically invisible because spellcasters won't use magic autonumosly out side of the magic realm. (I wish they would)